This paper aims to present ideas to bridge the gap between two conflicting views of information: Shannon information, which is used to model physical layer information, and semantic information, which is used in databases, distributed systems, human-computer interaction, and in the application layer of the OSI communication stack. We introduce the notion of a semantic domain, and define the amount of semantic information relative to a semantic domain. We show that translations between semantic domains achieve a consistent picture of semantic information. We indicate where and how the conceptual divide occurs between semantic information and Shannon information. We discuss mobile devices and users and a central server, as a possible setting for the application of the concepts developed in this paper. The discussion is aimed at pointing out the need for a unified theory, and at directions for how such a theory can be pursued.